Adjunctive intra-arterial thrombolysis after successful endovascular thrombectomy for large vessel occlusion: Meta-analysis of outcomes, dosage, and patient selection.

Background: Despite high recanalization rates with endovascular thrombectomy (EVT) for large vessel occlusions, functional outcomes remain suboptimal. This study investigates whether adjunctive intra-arterial (IA) thrombolysis following successful EVT can improve patient outcomes.

Methods: A systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. We searched Medline, Embase, Web of Science, and Cochrane databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for functional and safety outcomes.

Results: Seven trials (2131 patients) were included. IA thrombolysis was administered to 1081 (50.7%) patients. Patients receiving adjunctive IA thrombolysis had higher odds of excellent functional outcomes (modified Rankin Scale (mRS) 0-1) at 90 days (OR 1.44, 95% CI 1.21 to 1.72) compared with the EVT-alone group while maintaining similar rates of symptomatic intracerebral hemorrhage (sICH; OR 1.15, 95% CI 0.75 to 1.75). Subgroup analysis of excellent functional outcomes showed that the benefits of IA thrombolysis were primarily observed in specific patient populations: those treated with alteplase 0.225 mg/kg or tenecteplase 0.125 mg/kg, patients with lower expanded Thrombolysis in Cerebral Infarction (eTICI) scores, higher initial National Institutes of Health Stroke Scale (NIHSS), and those with cardioembolic etiology. Mortality rates and good functional outcomes (mRS 0-2) remained comparable between treatment groups.

Conclusion: Adjunctive IA thrombolysis following successful EVT may improve functional outcomes without added risk of sICH. Certain patient subgroups (those with lower recanalization rates, higher NIHSS, and cardioembolic etiology) and specific thrombolytic agents and dosages (alteplase 0.225 mg/kg, tenecteplase 0.125 mg/kg) appear to derive greater benefits from this approach. Further research is needed to validate these findings and refine patient selection.